The present invention relates to a method and apparatus for manufacturing a wire harness by using a nipped connector.
Wire harnesses have been widely used in electric appliances including automobiles and electronic musical instruments. A system using a clamped connector has sometimes been used in the manufacture of wire harnesses. However, when a clamped connector is used, an insulation coating must be removed from a wire, a contact must be clamped to catch the wire, and the wire with a contact is inserted in a connector. These manual operations require elaborated and complicated hand works, resulting in time-consuming operations and degrading work efficiency. An auxiliary component, i.e., the contact must be used in addition to the wire.
A nipped connector has been recently used in place of a clamping connector. When a wire is inserted in a connector through an upper opening thereof, a blade of a metal member with a terminal cuts the coating of the wire, and the metal wire is brought into contact with the metal member, thereby electrically connecting the wire to the terminal. In other words, when the wire is simply inserted in the connector under pressure, the wire can be electrically connected to the terminal, so that the connection operation is very simple and other auxiliary components are not required.
Even if a nipped connector is used, however, the manufacture of a wire harness still requires manual operation in the following manner. A wire is looped in a predetermined pattern, bound by binding members at predetermined positions and cut at these positions. Thereafter, connectors are nipped to the wires at the predetermined positions resulting in time-consuming operation and requiring much labor. As a result, the manufacturing operation is cumbersome.
The conventional manual operations are based on batch operations in consideration of efficiency. More particularly, patterning, binding, cutting, nipping and a conduction test of the wire are performed in separate steps. For this reason, when a nipping failure is found in any connector in the conduction test as the final step, the previous operations may often be in vein in accordance with the number and degree of nipping errors. The conventional batch operations cannot always prevent such operation loss. In addition, the manual operation is performed in accordance with control of fitters. Operation errors occur due to unskilledness, mistakes and exhaustion of the fitters. In particular, such operation errors tend to occur in patterning, cutting and nipping of the wire. Once an operation error occurs, the prepared wire harness cannot be used.
In general, since various types of wire harnesses are manufactured each in a small volume, model change often occurs. Along with this, wire patterns are frequently updated. Further operation errors thus often occur.
An automatic nipper has already been known to resolve the above problems. A plurality of wires are fed parallel to each other to parallel connectors and are automatically inserted by nipping punches in the corresponding connectors. In this automatic nipper, since the wires must be fed parallel to each other, the types of wire harnesses which can be manufactured are limited. For example, a wire harness having a structure wherein wires cross and are connected to arbitrarily selected terminals of the connector cannot be manufactured.